1. Field of the Invention
The present invention relates to a workpiece conveyor system, and to a workpiece hanger carriage for conveying a relatively large workpiece, such as an automobile, along an assembly line.
2. Description of Relevant Art
FIG. 5 of the accompanying drawings illustrates a conventional workpiece hanger carriage 1 movable along a rail 2 supported by posts 3 suspended from a ceiling. The carriage 1 includes a support frame 4 having rollers 5 rollingly engageable with the rail 2. The carriage 1 also includes a pair of laterally spaced arms 6 (only one shown) pivotally mounted on the frame 4 for supporting and releasing movement. A guide rail 7 is located adjacent to the rail 2 and upwardly curved for guiding a roller 8 to move the arms 6 away from each other for releasing a supported workpiece 9, such as an automobile at the end of an assembly line.
One of the problems with the prior workpiece hanger carriage is that the carriage, and hence the workpiece, are inclined forwardly and downwardly as the carriage moves along a downwardly curved portion of the rail to lower the workpiece for the release thereof, or any assembling operation to be performed thereon. Accordingly, the workpiece becomes positionally unstable on the carriage during such lowering movement.
Furthermore, the support arms of the prior carriage are located in such a position that they interfere with opening of the rear doors of a four-door automobile workpiece, making it difficult to attach various parts or effecting other assembling operations through the rear doors.
In addition, with the conventional arrangement, as many specially designed carriages are necessary as there are different types of automobiles or workpieces.